Interesting engine failure
09-26-2007, 10:48 PM
#1
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Recently a friend's engine blew, I'm a little perplexed as to EXACTLY why. Unfortunately I didn't build the engine, nor did I get to see it apart. Here is what he told me, the corner seal plugs were melted on both rotors side's that are fed by the secondary ports. Every apex seal was also cracked near those melted plugs. There was also melted rubber in the exhaust ports sleeves. He had broken in his fresh engine with I believe a little over a 1000 miles. He had a fmic, but his coolant and oil temps were super high( coolant 230/oil 240+ at times cruising), his intake temperatures were also nothing fantastic; 134ish. I suggest taking his intercooler off, and running just methanol injection, which he had yet to install. Well the coolant and oil temps did fall way down after he took off his IC, but his cruising intake temperatures were horrendous; 189ish up to 215. He did have his air filter sucking off the radiator. Ontop of this his alochol injector came loose and went through the motor, he said it took out one of the injector diffusers and took a chunk out of one rotor. He said all of this happened while crusing around and doing a little boost tuning( mainly transition work and low boost). He said the car became sluggish coming into boost, probably when the apex seals cracked, and then later something went wrong during boost and after that it was blown( probably when the alc injector went through the engine)
He did draw an interesting conclusion, he thinks the high intake temperatures while cruising killed the corner seal plugs, which inturn damaged the apex seals. While cruising the primary fuel injectors are cooling the intake charge, but only for the primary ports. Under boost the methanol and secondary injectors would be cooling the charge everywhere. The motor I believe does have some pretty large ports, I sure can hear a lot of overlap. Evidently no damage to the side or corner seals however.
It is interesting how this happened only week after the intercooler was taken off. However there could be a lot of other variables or things leading up to this. For example for the breakin period and when him and I were tuning up to 10psi, the base ignition timing was retarded by 90 degrees off of the pulley( timing marks were showing up at 9 o'clock on the pulley). I think i remember seeing egts in the downpipe up to 1600F briefly while cruising, that and those coolant and oil temperatures being really high. Now obviously the alky injector coming loose chipped that apex seals and took out that rotor housing, why were all of the apex seals cracked??
If anyone has any insight or experience into this, lets here it...
He did draw an interesting conclusion, he thinks the high intake temperatures while cruising killed the corner seal plugs, which inturn damaged the apex seals. While cruising the primary fuel injectors are cooling the intake charge, but only for the primary ports. Under boost the methanol and secondary injectors would be cooling the charge everywhere. The motor I believe does have some pretty large ports, I sure can hear a lot of overlap. Evidently no damage to the side or corner seals however.
It is interesting how this happened only week after the intercooler was taken off. However there could be a lot of other variables or things leading up to this. For example for the breakin period and when him and I were tuning up to 10psi, the base ignition timing was retarded by 90 degrees off of the pulley( timing marks were showing up at 9 o'clock on the pulley). I think i remember seeing egts in the downpipe up to 1600F briefly while cruising, that and those coolant and oil temperatures being really high. Now obviously the alky injector coming loose chipped that apex seals and took out that rotor housing, why were all of the apex seals cracked??
If anyone has any insight or experience into this, lets here it...
09-27-2007, 06:50 PM
#2
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Originally Posted by 1Revvin7' post='883577' date='Sep 26 2007, 08:48 PM
The motor I believe does have some pretty large ports, I sure can hear a lot of overlap.
The intake is 5* advanced and exhaust closing is no more than 1 or 2 degrees later in closing. The overlap is not very much, not sure how you could hear it. The ports are pretty good size, but this isnt related to the failure any way.
In that motor the primary port sides of the rotors had no problems with the corner seal plugs. The secondary side corner seal plugs were gone except for small evidence in the form of caked on burnt rubber that made the apex seals stick and difficult to remove. The plugs were almost completely vaporized and the apex seals are warped lengthwise (measured 3 and all were at .00015-.0002 inch), this tells me there was some intense heat going on in there! Was it high intake temps? Lean tuning? Who knows, but it wasn't from high water temps thats for sure.
What were the ambient conditions when those reported temps were recorded? If the 134 intake temps and 230/240 water/oil temps were measured on a 110 degree day considering a FMIC I dont think those temps were really too horrible. What was ambient when the 189-215 degree intake temps with no IC were taken?
From what we saw tearing this motor down I would be very cautions of not running an IC. I have seen some hot running engines torn down but never have I seen melted corner seal plugs! Running methanol as your fuel I believe would probably give enough cooling at cruise, but gasoline with no IC and no methanol injected at cruise looks to be a bad combination in this case.
09-28-2007, 11:02 AM
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Originally Posted by Tom93R1' post='883647' date='Sep 27 2007, 06:50 PM
The intake is 5* advanced and exhaust closing is no more than 1 or 2 degrees later in closing. The overlap is not very much, not sure how you could hear it. The ports are pretty good size, but this isnt related to the failure any way.
In that motor the primary port sides of the rotors had no problems with the corner seal plugs. The secondary side corner seal plugs were gone except for small evidence in the form of caked on burnt rubber that made the apex seals stick and difficult to remove. The plugs were almost completely vaporized and the apex seals are warped lengthwise (measured 3 and all were at .00015-.0002 inch), this tells me there was some intense heat going on in there! Was it high intake temps? Lean tuning? Who knows, but it wasn't from high water temps thats for sure.
What were the ambient conditions when those reported temps were recorded? If the 134 intake temps and 230/240 water/oil temps were measured on a 110 degree day considering a FMIC I dont think those temps were really too horrible. What was ambient when the 189-215 degree intake temps with no IC were taken?
From what we saw tearing this motor down I would be very cautions of not running an IC. I have seen some hot running engines torn down but never have I seen melted corner seal plugs! Running methanol as your fuel I believe would probably give enough cooling at cruise, but gasoline with no IC and no methanol injected at cruise looks to be a bad combination in this case.
In that motor the primary port sides of the rotors had no problems with the corner seal plugs. The secondary side corner seal plugs were gone except for small evidence in the form of caked on burnt rubber that made the apex seals stick and difficult to remove. The plugs were almost completely vaporized and the apex seals are warped lengthwise (measured 3 and all were at .00015-.0002 inch), this tells me there was some intense heat going on in there! Was it high intake temps? Lean tuning? Who knows, but it wasn't from high water temps thats for sure.
What were the ambient conditions when those reported temps were recorded? If the 134 intake temps and 230/240 water/oil temps were measured on a 110 degree day considering a FMIC I dont think those temps were really too horrible. What was ambient when the 189-215 degree intake temps with no IC were taken?
From what we saw tearing this motor down I would be very cautions of not running an IC. I have seen some hot running engines torn down but never have I seen melted corner seal plugs! Running methanol as your fuel I believe would probably give enough cooling at cruise, but gasoline with no IC and no methanol injected at cruise looks to be a bad combination in this case.
Tom glad you saw this, you've got more information than I was given. So there was rubber on the apex seals? Its kind of hard to tell if the burnt corner seals came first, or if that was just an event that happened when the apex seals warped and chipped. Its also hard to tell which direction each charge from each port is flowing etc, or if it was just extended conditions. I was leaning more towards just too high of intake temperature for low boost tuning. The intake temperatures were too high from running the air filter off the radiator w/ no IC, no doubt I've never seen intake temperatures that high. I've seen close to that high for intake temps on the 3rd gens here in the summer running open element air filters( sucking off the radiator).
As far as what I know about the tuning, after the IC came off, when I first started tuning intake temps at 2psi were 134F, and came down to 120F at 7psi. Afrs were in the high 10s. Car never at any point before or after the IC was above 11:1afr in boost, and never exceeded 10psi. Ignition maps were conservative, etc. I never saw leaner than a 14.9 while cruising. It was super lean in cruise for the breakin period when he first brought it here. However the first time I tuned the car when he had the fmic, after about 10 minutes of tuning and getting the car to be very closed to dial into for up to 10psi the car started randomly breaking up in boost, then consistently breaking up. We did probably 4 or so more rolls into the boost and it kept happening no matter what was done in the ecu to fuel or timing. Thats when I suspected the timing wasn't setup correctly and indeed it was way off, that in combination with his alternator erraticly flaking out was the source of the breakup. After that was fixed his tune was way off again. I can't tell you what happened while it blew as far as afr/intake temp etc, I wasn't there.
As far as cruise afrs, its hard to say what he was seeing for the prolong time outside of when we used my meter. His setup was changing all the time, along with not having tuned any of the correction maps. Its so hard to pinpoint if it was a prolonged problem, or just a mistake while he was tuning in combination with the high intake temps, or not even a mistake, but the first time the car was tuned with engine setup being correct( he had just fixed his charging issue and said the car was a lot better) in combination with low vacuum/low boost( under 3psi) high intake temperatures.
09-28-2007, 11:14 PM
#5
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Originally Posted by 1Revvin7' post='883679' date='Sep 28 2007, 09:02 AM
Tom glad you saw this, you've got more information than I was given. So there was rubber on the apex seals? Its kind of hard to tell if the burnt corner seals came first, or if that was just an event that happened when the apex seals warped and chipped. Its also hard to tell which direction each charge from each port is flowing etc, or if it was just extended conditions. I was leaning more towards just too high of intake temperature for low boost tuning. The intake temperatures were too high from running the air filter off the radiator w/ no IC, no doubt I've never seen intake temperatures that high. I've seen close to that high for intake temps on the 3rd gens here in the summer running open element air filters( sucking off the radiator).
As far as what I know about the tuning, after the IC came off, when I first started tuning intake temps at 2psi were 134F, and came down to 120F at 7psi. Afrs were in the high 10s. Car never at any point before or after the IC was above 11:1afr in boost, and never exceeded 10psi. Ignition maps were conservative, etc. I never saw leaner than a 14.9 while cruising. It was super lean in cruise for the breakin period when he first brought it here. However the first time I tuned the car when he had the fmic, after about 10 minutes of tuning and getting the car to be very closed to dial into for up to 10psi the car started randomly breaking up in boost, then consistently breaking up. We did probably 4 or so more rolls into the boost and it kept happening no matter what was done in the ecu to fuel or timing. Thats when I suspected the timing wasn't setup correctly and indeed it was way off, that in combination with his alternator erraticly flaking out was the source of the breakup. After that was fixed his tune was way off again. I can't tell you what happened while it blew as far as afr/intake temp etc, I wasn't there.
As far as cruise afrs, its hard to say what he was seeing for the prolong time outside of when we used my meter. His setup was changing all the time, along with not having tuned any of the correction maps. Its so hard to pinpoint if it was a prolonged problem, or just a mistake while he was tuning in combination with the high intake temps, or not even a mistake, but the first time the car was tuned with engine setup being correct( he had just fixed his charging issue and said the car was a lot better) in combination with low vacuum/low boost( under 3psi) high intake temperatures.
As far as what I know about the tuning, after the IC came off, when I first started tuning intake temps at 2psi were 134F, and came down to 120F at 7psi. Afrs were in the high 10s. Car never at any point before or after the IC was above 11:1afr in boost, and never exceeded 10psi. Ignition maps were conservative, etc. I never saw leaner than a 14.9 while cruising. It was super lean in cruise for the breakin period when he first brought it here. However the first time I tuned the car when he had the fmic, after about 10 minutes of tuning and getting the car to be very closed to dial into for up to 10psi the car started randomly breaking up in boost, then consistently breaking up. We did probably 4 or so more rolls into the boost and it kept happening no matter what was done in the ecu to fuel or timing. Thats when I suspected the timing wasn't setup correctly and indeed it was way off, that in combination with his alternator erraticly flaking out was the source of the breakup. After that was fixed his tune was way off again. I can't tell you what happened while it blew as far as afr/intake temp etc, I wasn't there.
As far as cruise afrs, its hard to say what he was seeing for the prolong time outside of when we used my meter. His setup was changing all the time, along with not having tuned any of the correction maps. Its so hard to pinpoint if it was a prolonged problem, or just a mistake while he was tuning in combination with the high intake temps, or not even a mistake, but the first time the car was tuned with engine setup being correct( he had just fixed his charging issue and said the car was a lot better) in combination with low vacuum/low boost( under 3psi) high intake temperatures.
Well I tell ya, I have an engine that tells me your setup does not work....Please provide real data , that would contradicts this, please.
09-30-2007, 02:18 PM
#6
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As said before running an air filter off the radiator without an intercooler results in having the same intake temperatures as your coolant.
Thats not how we build cars here, definitely not " my setup ".
Thanks for the informative post Glen.
Thats not how we build cars here, definitely not " my setup ".
Thanks for the informative post Glen.
09-30-2007, 03:45 PM
#7
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Originally Posted by 1Revvin7' post='883815' date='Sep 30 2007, 12:18 PM
As said before running an air filter off the radiator without an intercooler results in having the same intake temperatures as your coolant.
Thats not how we build cars here, definitely not " my setup ".
Thanks for the informative post Glen.
Thats not how we build cars here, definitely not " my setup ".
Thanks for the informative post Glen.
Again I have proof your setup was the cause of this engine failing. I was not providing information in my above post I am looking for data that supports you setup working.
People, I am not looking for a fight as Elliot sure seems set on a childish rant, I mearly am looking for him to provide real hard data that contradicts my conclusions as a professional.
Fact is this setup is based in theory, not real data, as you can see from his posts he has no intent in providing real infomation.
We deliver many engines with the same configuration as the above mentioned engine with no issues....
If the customer had not relied on Elliots suggestion to remove the intercooler the engine would be running today.
09-30-2007, 05:18 PM
#8
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Some of you may be wondering what Elliot is talking about when he says intake sucking from radiator....Here is a pick of the air filter on the car in question. Oh and it is not the best setup but if it would have been left alone, the engine would be alive today.
Having the air filter near the radiator is going to of cousre pull in hot hair however the intercooler is going to cool it owner knows I would rather have his filter out of the way of the radiator), unless you are not using one and trying to cool with just methanol, this is Elliot big idea, how about air at cruising?? The turbo is still putting out hot air but at cruise there is not injection...part throttle detonation any one!
Having the air filter near the radiator is going to of cousre pull in hot hair however the intercooler is going to cool it owner knows I would rather have his filter out of the way of the radiator), unless you are not using one and trying to cool with just methanol, this is Elliot big idea, how about air at cruising?? The turbo is still putting out hot air but at cruise there is not injection...part throttle detonation any one!
09-30-2007, 07:33 PM
#9
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There are several rotary powered vehicles here running w/o an intercooler just fine. We did an Rx-4 this way several years ago, again no problems. I'm not the only one that does this, I'm not reinventing the wheel in any way. You sure are hostile, chill out...